VISUALLY GUIDED SACCADE VERSUS EYE-HAND REACH: CONTRASTING NEURONAL ACTIVITY IN THE CORTICAL SUPPLEMENTARY AND FRONTAL EYE FIELDS. MUSHIAKE, HAJIME, NAOTAKA FUJII, AND, JUN TANJI. Department of Physiology, Tohoku university School of Medicine, Sendai, 980, Japan.
APStracts 3:0033N, 1996.
SUMMARY AND CONCLUSIONS
1. We studied neuronal activity in the supplementary eye field (SEF) and frontal eye field (FEF) of a monkey during performance of a conditional motor task that required capturing of a target either with a saccadic eye movement (the saccade-only condition) or with an eye-hand reach (the saccade-and-reach condition), according to visual instructions. 2. Among 106 SEF neurons that showed presaccadic activity, more than half of them (54%) were active preferentially under the saccade-only condition (n=12) or under the saccade- and-reach condition (n=45), while the remaining 49 neurons were equally active in both conditions. 3. In contrast, most (97%) of 109 neurons in the FEF exhibited approximately equal activity in relation to saccades under the two conditions. 4. The present results suggest a possibility that SEF neurons, at least in part, are involved in signaling whether the motor task is oculomotor or combined eye-arm movements, whereas FEF neurons are mostly related to oculomotor control.

Received 5 October 1995; accepted in final form 29 January 1995.
APS Manuscript Number J668-5.
Article publication pending J. Neurophysiol.
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 14 February 96